The invention relates to liquid cleaning compositions consisting of at least two partial compositions which are stored separate from each other in a single container comprising at least two chambers, and which are mixed on use, one partial composition comprising a peroxygen bleach compound.
The compositions are intended for cleaning and disinfecting household surfaces and are particularly well adapted for use on surfaces which are non-horizontal (i.e. sloping or vertical) as can be found e.g. in bathrooms and toilets.
Compositions which clean and disinfect for use on non-horizontal surfaces presently comprise solutions of alkali metal hypochlorite to be poured, squirted or sprayed onto the surface. Such solutions are thickened so as to prevent them from draining off the surface too quickly. Particularly for toilet cleaning purposes they are often marketed packed in containers provided with a spout such that they may be delivered to the surface by squeezing the container. Sometimes such spouts are mounted on the container in such a way that the squirt of liquid produced by the squeezing action may be more easily directed to corners or under rims which cannot easily be reached otherwise.
One problem with said compositions is that hypochlorite has an unpleasant odour and, when accidentally mixed with an acidic product, it can liberate toxic amounts of chlorine gas. Other bleaching agents are known, particularly peroxides. However, peroxides are often either unstable on storage in formulations or exhibit poor bleaching performance at a pH at which they are storage stable.
Toothpastes and peroxide-based hair bleaching compositions have been formulated as weakly acidic peroxide solutions or gels, which are mixed with separate weakly alkaline solutions or pastes just before use. The known advantage of this form of product is that under acidic conditions the peroxide is more stable to decomposition, but is more effective as a bleaching agent under alkaline conditions.
Other two-part peroxide based compositions are disclosed in JP-A-60/038497 (LION BRANDS), which relates to a foaming, two-part drain cleaning composition which comprises:
a) 0.5-50%wt hydrogen peroxide,
b) alkali, having an alkalinity 0.1-50% based on sodium hydroxide,
c) surface active agent in (a) or (b), and,
d) terpene alcohol/cyclic terpene alcohol in (a) or (b).
The compositions (a) and (b), including the surfactants and terpene are sequentially or simultaneously dosed into a toilet bowl and pass into the drains where the composition produces a body of foam which acts to clean or if necessary unblock the drain.
Other forms of simultaneous delivery of two components are known. Thus, U.S. Pat. No. 3,760,986 discloses a dispensing bottle for dispensing two separate fluids to a common point. Such a bottle is formed with an opening at the top and a divider extending through the interior of the bottle to define two compartments which provide dual reservoirs for fluids. The apparatus disclosed further comprises a pump means to simultaneously withdraw fluid from each compartment, via separate draw tubes, and discharge the fluid to a common point. This device enables an alkaline and an acid material to be stored separately and sprayed from a single unit to a common point.
WO 95/16023 discloses a container comprising two chambers or reservoirs, one containing a liquid acid or neutral composition comprising a peroxide compound and the other containing a liquid alkaline composition. The container is provided with a spray system able to either produce a single spray of a mixture of the two components or two simultaneous sprays of each component directed to the same point on a surface whereafter the components mix on the surface. The product is delivered as fine droplets which coalesce on the surface which provides for easy and complete mixing of the two compositions. It is described that the compositions may be thickened as is or they may contain a thickener system which thickens on mixing. The thickening system is particularly geared to improve the spraying characteristics and prevent respiratory irritation caused by very fine droplets. The examples show both components to be thickened before spraying.
WO 97/31087 discloses a container comprising two chambers or reservoirs, one containing a liquid composition comprising a peroxygen bleach and the other containing a liquid composition comprising a builder or chelating agent and at least one of these liquids containing a pH adjusting agent which on mixing of the liquids brings the pH of the mixture to a value at which the peroxygen bleach is effectively cleaning as well as stable. Preferably the peroxygen bleach is either a peracid or a persalt and the pH is between 9.0 and 11.5. The two liquid compositions are mixed on delivery to the surface, preferably by a spray system. A similar system is described in WO 98/23533 in which a combination of hydrogen peroxide and a tertiary N-alkyl ammonium acetonitrile salt from one chamber and an alkaline solution from another chamber may be deliverd to a surface by spraying.
These prior art two component peroxide cleaning systems have the disadvantage that a spray system is only able to deliver a limited amount of product to a surface and is unable to reach difficultly accessible places since the container generally must be held vertically. Therefore they are less suitable for toilet cleaning purposes. Moreover, spray systems such as trigger spray heads and pump sprays are relatively expensive, particularly those which are suitable for multicompartment containers.